A231971 Number of (n+1) X (2+1) 0..1 arrays with no element having a strict majority of its horizontal and vertical neighbors equal to one.

16, 56, 169, 550, 1764, 5680, 18225, 58596, 188356, 605458, 1946025, 6255180, 20106256, 64627982, 207734569, 667725402, 2146283584, 6898841796, 22175081569, 71277802674, 229109651716, 736431677100, 2367126871209, 7608702637640

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 3*a(n-1) + 2*a(n-3) + 4*a(n-4) - 10*a(n-5) - 2*a(n-6) - a(n-8) + a(n-9).

Empirical g.f.: x*(16 + 8*x + x^2 + 11*x^3 - 62*x^4 - 14*x^5 + x^6 - 5*x^7 + 6*x^8) / ((1 - 3*x - x^2 + x^3)*(1 + x^2 - 3*x^4 - x^6)). - Colin Barker, Oct 01 2018

Example

Some solutions for n=2:
..0..0..1....1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..1
..1..0..0....0..0..1....1..0..1....0..0..0....0..0..0....0..1..0....1..0..0
..0..0..0....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....1..0..0

Crossrefs

Column 2 of A231977.

Sequence in context: A039451 A279063 A331766 * A333279 A304692 A295986

Adjacent sequences: A231968 A231969 A231970 * A231972 A231973 A231974

Keyword

nonn

Author

R. H. Hardin, Nov 16 2013

Status

approved